Lignans from the Bark ofZanthoxylum planispinum

Phenolic Compounds in Bacterial Inactivation: A Perspective from Brazil

Phenolic compounds are natural substances that are produced through the secondary metabolism of plants, fungi, and bacteria, in addition to being produced by chemical synthesis. These compounds have anti-inflammatory, antioxidant, and antimicrobial properties, among others. In this way, Brazil represents one of the most promising countries regarding phenolic compounds since it has a heterogeneous flora, with the presence of six distinct biomes (Cerrado, Amazon, Atlantic Forest, Caatinga, Pantanal, and Pampa). Recently, several studies have pointed to an era of antimicrobial resistance due to the unrestricted and large-scale use of antibiotics, which led to the emergence of some survival mechanisms of bacteria to these compounds. Therefore, the use of natural substances with antimicrobial action can help combat these resistant pathogens and represent a natural alternative that may be useful in animal nutrition for direct application in food and can be used in human nutrition to promote health. Therefore, this study aimed to (i) evaluate the phenolic compounds with antimicrobial properties isolated from plants present in Brazil, (ii) discuss the compounds across different classes (flavonoids, xanthones, coumarins, phenolic acids, and others), and (iii) address the structure-activity relationship of phenolic compounds that lead to antimicrobial action.

An Unusual Tetrahydrofuran Lignan from the Roots of Zanthoxylum planispinum and the Potential Anti-inflammatory Effects

An unusual tetrahydrofuran lignin, zanthplanispine (1), together with 14 known lignans (2 - 15) were isolated from the AcOEt-soluble fraction from the MeOH extract of Z. planispinum roots. The structures of 1 was elucidated on the basis of 1D- and 2D-NMR experiments as well as HR-ESI-MS analysis. The known compounds were identified by the comparison of their NMR data with previously reported in the literatures. Bioassay showed that compounds 1 - 4 could inhibit nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. In particular, compound 1 showed significant inhibitory activity with an IC₅₀ value of 36.8 μm.

A New Lignan from the Leaves of Zanthoxylum armatum

A new furofuran lignan, zanthonin (1) together with 13 known compounds including seven furofuran lignans (2–8), one isobutyl amide (9), a furanocoumarin (10) and four flavonoids (11–14) have been isolated from the leaves of Zanthoxylum armatum. The chemical structures of these compounds were elucidated mainly on the basis of NMR (1D and 2D) and MS data. This is the first report on the isolation of methylxanthoxylol (4) from Z. armatum.

Coumarins and lignans from Zanthoxylum schinifolium and their anticancer activities

Zanthoxylum schinifolium is an aromatic shrub, and its pericarp and leaves are widely used in culinary applications in East Asian countries. It has also long been used in traditional Oriental medicine for treating the common cold, stomach ache, diarrhea, and jaundice. In this study, we identified two new compounds, zanthoxyloside (1) and schinifolisatin A (13), along with 23 known coumarins (2-12) and lignans (14-25), from a methanol extract of the stems of Z. schinifolium . The chemical structures of the compounds were determined by mass, 1D-, and 2D NMR spectroscopy. The anticancer effects of the isolated compounds were examined in three human cancer cell lines. Compounds 10-12 significantly reduced the proliferation of HL-60 human acute promyelocytic leukemia cells with IC50 values of 4.62-5.12 μM. Treatment of PC-3 prostate cancer cells and SNU-C5 colorectal cancer cells with compound 10 resulted in potent antiproliferative activity, with IC50 values of 4.39 and 6.26 μM, respectively. Also, compounds 10-12 induced the apoptosis of three cancer cells. Furthermore, the induction of apoptosis was accompanied by down-regulation of p-ERK1/2 MAPK, p-AKT, and c-myc levels, in a time-dependent manner. These data suggested that compounds 10-12 from Z. schinifolium have potential in cancer treatment.

Two dimeric lignans with an unusual α,β-unsaturated ketone motif from Zanthoxylum podocarpum and their inhibitory effects on nitric oxide production

Two new dimeric lignans, zanthpodocarpins A (1) and B (2), and five known lignans, eudesmin (3), (1R,2R,5R,6S)-2-(3,4-dimethoxyphenyl)-6-(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (4), dimethoxysamin (5), rel-(1R,5R,6S)-6-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-2-one (6), and magnone A (7), were isolated from the barks of Zanthoxylum podocarpum. Their structures were identified by using spectroscopic methods. Compounds 1 and 2 are rare dilignans bearing an unusual α,β-unsaturated ketone group from a natural source. Bioassay showed that compounds 1 and 2 could inhibit nitric oxide (NO) production in LPS stimulated RAW 264.7 cells with IC(50) values of 5.31 μM and 12.15 μM, respectively.

Anti-listerial compounds from Asari Radix

Asari Radix, the roots of Asarum heterotropoides F. Maekawa var. manshuricum F. Maekawa or A. sieboldii F. Maekawa, has traditionally been used for the treatment of various infectious diseases. Since its MeOH extract inhibited the growth of Listeria monocytogenes in a preliminary test, the aim of this study was to isolate and identify the anti-listerial compounds from the plant. Activity-guided fractionation led to the isolation of seven compounds 1-7 from the MeOH extract, and their chemical structures were identified by comparison of the spectroscopic data with those in the literature. Compounds 1-7 exhibited inhibitory activity against all five tested strains of L. monocytogenes with diameter of inhibition zones ranging from 7 to 11 mm in the agar disc diffusion method. Compounds 1-3 and 7 demonstrated potent antimicrobial effects on the L. monocytogenes strains, with MICs between 62.5 and 125 μg/mL. This is the first report that AR possesses inhibitory activity against L. monocytogenes.